Thermoplastic resin composition, process for manufacture and use thereof

ABSTRACT

The present invention relates to a thermoplastic resin composition comprising (A) ionomer of ethylene/(meth)acrylic acid copolymer 60 to 96.7% by weight, (B) ethylene or alpha-olefin/glycidyl monomer copolymer 0.3 to 10% by weight and (C) propylene/alpha-olefin copolymer 3 to 30% by weight. The resin composition has excellent processability, workability, visual qualities, abrasion resistance, scratch resistance, surface hardness, stain resistance, heat resistance, etc, and is usable for building materials such as handrails, flooring materials and wall papers; car interior-exterior parts, toys, stationery, sundries, etc.

TECHNICAL FIELD

The present invention relates to a thermoplastic resin composition thatcan produce a molded article having good processability, workability,scratch resistance, abrasion resistance, stiffness, surface hardness,stain resistance, heat-resistance and visual qualities (mattedappearance), and having surface properties that the sliding frictioncoefficient is small; a process for manufacture and a use thereof. Morespecifically, the present invention relates to the thermoplastic resincomposition, containing an ionomer as major component, which is suitablefor use of building materials such as flooring materials, handrails andwall papers, car interior-exterior parts, toys, stationery and sundries;the process for manufacture and the use thereof.

BACKGROUND ART

An ionomer in which carboxyl group of an ethylene/(meth)acrylic acidcopolymer, containing 2 to 30% by weight of unsaturated carboxylic acid,is neutralized by metal ion, shows excellent abrasion resistance andtransparency due to ion crosslinkage when compared with other ethylenecopolymers. It has been already known by Japanese laid-open PatentApplication SHO 60(1985)-127149, for example, that the ionomer is usedfor improving surface scratch resistance of building materials and carinterior-exterior parts utilizing such properties. It is described inthe publication that car interior-exterior materials having excellentsurface gloss and scratch resistance can be obtained. It is also knownby Japanese laid-open Patent Application HEI 8(1996)-254004 that inbuilding material sector, the ionomer resin is used for an surface layerof non-PVC type flooring materials in order to prevent abrasion andscratch of the materials, which are caused by moving desks or chairs, ordue to friction in walking.

The above mentioned moldings whose surface layer is ionomer, however,requires a measure coping with excessive gloss due to good transparencyand surface smoothness which are characteristics of ionomer. Forexample, a method such as making matted pattern with embossing roll hasbeen taken. This method, however, has a defect that it was difficult toput it use in producing a three-dimensional type molding such ashandrail or pipe by profile extrusion.

Further, even if a matted sheet is produced using embossing roll, therewas such a problem that matted pattern disappears when the above sheetis put into a foam oven in the process of heating secondarily such asmanufacturing a foamed sheet. For resolving the problem, the followingtwo methods have been taken. One is to maintain matted appearance bylaminating a matted film on the foamed sheet after the process of thefoam oven. And the other is to make matted pattern on the foamed sheetagain by passing through the embossing roll. Nevertheless, the problemin the case of putting it to practical use has been pointed out. Thatis, trouble which the foamed sheet often melts to stick to heat roll dueto the properties of ionomer easy to adhere to metal.

Different from the above method, some ways that cause matted appearanceto the resin itself are already known. For example, the ways blendingpolymers having poor compatibility each other or adding a polymer suchas a rubber-like material having different degree of viscosity are knownby Japanese laid-open Patent Application SHO 61(1986)-37836 or Japaneselaid-open Patent Application HEI 4(1992)-86260, etc. As a similar way tothese, use of an ionomer composition modified with styrene/unsaturatedcarboxylic acid copolymer is known by Japanese laid-open PatentApplication HEI 11(1999)-140251, and the effects of matted appearanceand improved heat-resistant are confirmed. Nevertheless, since they arethe ways using the poor compatibility, the ionomer composition stillpossesses some problems which spoil the characteristics of ionomer, suchas strong whitening when the sheet is folded, decrease of abrasionresistance, etc.

For the above reasons, the present inventors have studied ways addingthe heat resistance and the matted properties without causing thewhitening by folding, while best utilizing excellent abrasion resistanceand scratch resistance of ionomers. As the result, we have finally foundthat the ionomer composition having required performance can be obtainedwhen blending ionomer with ethylene copolymer and propylene/α-olefincopolymer mentioned below in specific amount ratio. We have also foundthat the composition can provide moldings having high stiffness, highsurface hardness and good slipping properties.

Therefore, an object of the present invention is to provide athermoplastic resin composition which has excellent processability,workability, abrasion resistance, scratch resistance, stiffness, surfacehardness, stain resistance, visual qualities (matted appearance),heat-resistance, etc. Another object of the present invention is toprovide a molded article obtained from the composition having excellentsurface characteristics, and especially, to provide a surface materialfor multi-layer material showing excellent surface characteristics.

DISCLOSURE OF THE INVENTION

The present invention relates to a thermoplastic resin compositioncomprising 60 to 96.7 parts by weight of (A) an ionomer wherein 20 to90% of carboxyl group of ethylene/(meth)acrylic acid copolymer isneutralized by metal ion; 0.3 to 10 parts by weight of (B) a copolymerof ethylene or α-olefin, containing glycidyl (meth)acrylate orunsaturated glycidyl ether, optionally further containing vinyl ester orunsaturated carboxylic acid ester; and 3 to 30 parts by weight of (C) apropylene/α-olefin copolymer.

The present invention also relates to a method for producing the abovementioned thermoplastic resin composition having various excellentproperties and to the application of said thermoplastic resincomposition.

PREFERRED EMBODIMENTS OF THE INVENTION

Ionomer (A) used in the present invention is the one wherein 20 to 90mol %, preferably 30 to 85 mol % of the carboxyl group of theethylene/(meth)acrylic acid copolymer is neutralized by metal ion. Next,the ethylene/(meth)acrylic acid copolymer as a base polymer is acopolymer wherein the content of (meth)acrylic acid is in the range of 2to 30% by weight, preferably 3 to 25% by weight, and may be not onlycopolymer of ethylene and acrylic or methacrylic acid but alsomulti-monomer type copolymer wherein (an)other monomer(s) is(are)optionally copolymerized. In the case of using ionomer whose acidcontent is less than the above range, it is difficult to obtain acomposition having excellent abrasion resistance and matted appearance.

As other monomer which may copolymerize optionally, there can beexemplified vinyl ester such as vinyl acetate, vinyl propionate;unsaturated carboxylic acid ester such as methyl acrylate, ethylacrylate, isopropyl acrylate, isobutyl acrylate, n-butyl acrylate,isooctyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethylmethacrylate, isobutyl methacrylate, dimethyl maleate, diethyl maleate;carbon monoxide and sulfur dioxide. Though the monomer may becopolymerized in the range of 0 to 40%, preferably 0 to 30% by weight,an increase in the content of the other monomer generally makes itharder to obtain a composition having excellent abrasion resistance,scratch resistance and heat resistance. Therefore, it is preferable touse the copolymer not containing the other monomer, or even if itcontains the other monomer, it is preferable to use it containing themonomer in the range of not more than 20% by weight.

It is desirable to use the ethylene/(meth)acrylic acid copolymer whichhas a melt flow rate in a range of 1 to 1000 g/10 min, preferably 2 to800 g/10 min, as determined at a temperature of 190° C. and under a loadof 2160 g. The above copolymer can be obtain by radical copolymerizationunder high temperature and high pressure.

Ionomer (A) wherein 20 to 90 mol %, preferably 30 to 85 mol % ofcarboxyl group of the above copolymer is neutralized with metal ion isused. In this case, as metal ion, divalent metal such as zinc oralkaline earth metal, for example, magnesium and calcium are preferable.A combination of divalent metal and other metal, for example, alkalimetal such as lithium, sodium and potassium, may be used. That is, byusing divalent metal for at least one part of metal ions, a compositionhaving excellent matted appearance (silky appearance), heat resistance,retention of matted pattern, etc, can be obtained easier comparing withionomer containing alkali metal singly or alkali metals in combination,which do not contain any divalent metals.

Further, considering molding properties, mechanical properties,miscibility with other component, etc, ionomer having a melt flow ratein a range of 0.01 to 100 g/10 min, more desirably 0.1 to 50 g/10 min,as determined at 190° C. under a load of 2160 g is preferably used.

In the present invention, copolymer (B) is a copolymer of ethylene orα-olefin, containing glycidyl (meth)acrylate or unsaturated glycidylether, optionally further containing vinyl ester or unsaturatedcarboxylic acid ester, wherein the α-olefin has about 3 to 8 carbonatoms such as propylene or 1-butene. As the component (B), the copolymerof ethylene is especially preferable.

As glycidyl (meth)acrylate or unsaturated glycidyl ether, glycidylacrylate, glycidyl methacrylate, vinyl glycidyl ether, allyl glycidylether, 2-methyl allyl glycidyl ether, etc, can be cited.

The copolymer of ethylene or α-olefin with above mentioned glycidylmonomer does not need to be a binary copolymer and may be amulti-monomer type copolymer in which (an) other monomer(s), forexample, vinyl ester or unsaturated carboxylic acid ester is(are)copolymerized. Examples of other monomer can be the monomer alreadygiven above as other monomer of ethylene/(meth)acrylic acid copolymerwhich is the base polymer of ionomer (A). Moreover, in the presentinvention, multi-monomer type copolymer containing ethylene, α-olefinand the above mentioned glycidyl monomer can be used.

In the (B) copolymer of ethylene or α-olefin with glycidyl monomer,ethylene or α-olefin is preferably contained in the range of 50 to 99%by weight, especially 52 to 98% by weight, glycidyl monomer in the rangeof 0.5 to 20% by weight, especially 1 to 18% by weight, and the abovementioned other monomer in the range of 0 to 49.5% by weight, especially0 to 40% by weight. When the content of glycidyl monomer is too low,improvement of heat resistance and retention of matted pattern is notremarkable. On the other hand, when the content is too high, reactivityto ionomer is too high and sometimes a problem to cause a difficulty ofmolding due to increase of the resin viscosity and/or to cause gelformation in the composition may occur.

The above copolymer may be a random copolymer or a graft copolymer.Generally, it is preferable to use random copolymer in view ofuniformity of reaction to ionomer. The random copolymer can be obtainedby radical copolymerization under a condition of high temperature andhigh pressure.

In the case of using ethylene copolymer as the above mentionedcopolymer, it is preferable to use copolymer having a melt flow rate ina range of 0.01 to 1000 g/10 min, especially 0.1 to 200 g/10 min asdetermined at 190° C. under a load of 2160 g.

In the present invention, (C) propylene/α-olefin copolymer is used with(A) ionomer and (B) copolymer of ethylene or α-olefin with glycidylmonomer. By using the propylene/α-olefin copolymer that can be easilydispersed in other components, a resin composition having excellentvisual qualities, heat-resistance, abrasion resistance, scratchresistance, stain resistance, mechanical strengths, etc, can easily beobtained.

Propylene/α-olefin copolymer (C) used in the present invention is acopolymer of propylene as a main component and other α-olefin, which hasa density of preferably 870 to 930 kg/m³, more preferably 880 to 920kg/m³ and a melt flow rate of preferably 0.1 to 100 g/10 min, morepreferably 0.2 to 80 g/10 min as determined at 230° C. under a load of2160 g.

In the copolymer (C), α-olefin copolymerized with propylene preferablyhas 2 to 12 carbon atoms, more preferably 2 to 10 carbon atom/s.Specifically, as the α-olefin, ethylene, 1-buten, 1-hexene, 1-octene,1-decene, 1-dodecen, 4-methyl-1-pentene, can be exemplified. Theα-olefin may be a single, or two or more kinds.

The copolymer (C) may be a random copolymer or a block copolymer.Especially suitable random copolymer is a random copolymer of propyleneand ethylene or a random copolymer of propylene, ethylene and (an)otherα-olefin(s), wherein the content of propylene is in the range of 85 to99.9% by weight, preferably 90 to 99.5% by weight. These are crystallinepolymers produced by copolymerization in the presence of astereospecific catalyst.

The above block copolymer which can be used as copolymer (C), can beobtained by polymerization or copolymerization of propylene and otherα-olefin in sequential manner. Generally the block copolymerization iscarried out by combining one or more polymerization stages comprising(2) copolymerization of propylene and a little much α-olefin and/or (3)polymerization of α-olefin, after (1) polymerization of propylene. Inthe above (1) polymerization of propylene, there is a case ofcopolymerizing small amount of α-olefin. And there is another case ofcopolymerizing small amount of propylene in the (3) polymerization ofα-olefin. In either case, the above block copolymer can be obtained bythe above multi stage polymerization in the presence of a stereospecificcatalyst. The suitable propylene/α-olefin block copolymer is a blockcopolymer of propylene and ethylene containing about 60 to 95% by weightof (1) propylene polymer block.

A blend ratio of each component (A), (B) and (C) in the thermoplasticresin composition of the present invention, is such a ratio as 60 to96.7 parts by weight of ionomer (A), 0.3 to 10 parts by weight ofcopolymer (B) and 3 to 30 parts by weight of propylene/α-olefincopolymer (C), preferably 73 to 95.5 parts by weight of (A), 0.5 to 7parts by weight of (B) and 4 to 20 parts by weight of (C), morepreferably 81 to 94 parts by weight of (A), 1 to 4 parts by weight of(B) and 5 to 15 parts by weight of (C), when these total quantity is 100parts by weight.

The thermoplastic resin composition of the present invention can beobtained by melt-blending ionomer (A), ethylene or α-olefin/glycidylmonomer copolymer (B) and propylene/α-olefin copolymer (C). On theoccasion of melt-blending, common blending devices such as screwextruder, roll mixer and Banbury mixer can be used. In addition,although melt-blending can be conducted by combining above threecomponents simultaneously, most preferred is the way of melt-blending(B) and (C) beforehand, and then melt-blending with (A). This method hasan advantage to stably produce the composition having many superiorproperties with good quality, because (B) is diluted by (C) and then itleads to uniform and not local reaction to (A). The method like mixing(C) after melt-blending (A) and (B) should be avoided, because gelsmight be formed by local reaction, when such a method is applied.

In the resin composition of the present invention, within limits notdetracting the object of the present invention, other polymers andvarious additives can be compounded. As an example of such otherpolymers, other polyolefin such as ethylene/α-olefin copolymer having adensity of 870 to 930 kg/m³, for example, which is produced by ametallocene catalyst; and linear low density polyethylene which isproduced by other type of catalyst; can be cited. Said other polyolefincan be combined in a ratio of, for example, not more than 10 parts byweight to 100 parts by weight of the total of the above (A), (B) and(C).

In addition, as the above additives, antioxidants, heat stabilizers,light stabilizers, ultraviolet absorption agents, pigments, dye stuffs,slipping agents, anti-blocking agents, antistatic agents, anti-moldagents, antibacterial agents, flame retardants, flame retardant aids,cross linking agents, cross linking co-agents, foaming agents, foamingco-agents, inorganic fillers and fibrous reinforcements can beexemplified.

The resin composition of the present invention can be molded intovarious shapes of articles by various molding methods such as extrusionmolding, injection molding, compression molding and blow molding. Forexample, a molded article such as sheet or film produced using blownfilm machine or cast film/sheet machine exhibits matted (silky)appearance and has characteristics of excellent stiffness, surfacehardness, stain resistance and visual qualities (matted appearance),while maintaining characteristics of ionomer such as non-whitening atstretching or folding, excellent abrasion resistance and scratchresistance. The molded article such as sheet or film may be a mono-layeror a laminate with an adhesive resin, where the laminate is produced bycoextrusion molding machine in order to improve adhesive properties withvarious substrates.

A representative example of the adhesive resin laminated on resincomposition of the present invention can be a single resin or blend oftwo or more resins selected from ethylene/unsaturated carboxylic acidcopolymer, ethylene/unsaturated carboxylic acid/unsaturated carboxylicacid alkyl ester terpolymer, ethylene/unsaturated carboxylic acid alkylester copolymer, ethylene/vinyl ester copolymer, ethylene/unsaturatedcarboxylic acid alkyl ester/carbon monoxide terpolymer and graftedproducts of these copolymer/terpolymer with an unsaturated carboxylicacid.

In order to improve antistatic properties and high frequency welderproperties of the sheet and film obtained from the resin composition ofthe present invention, the composition may be coextruded with a specificpotassium ionomer, a composition of the potassium ionomer withpolyhydric alcohol, or a composition further with optional ethylenepolymer, by using various molding methods, preferably by coextrusionmolding machine. Even if an antistatic agent is not added to the resincomposition of the present invention, the potassium ionomer layerlaminated plays a role to remarkably reduce charge decay time of theresin composition layer. On this account it is desirable to use thepotassium ionomer, the composition of the potassium ionomer withpolyhydric alcohol, or the composition further with optional ethylenepolymer, having surface resistivity of not more than 10¹¹Ω, preferablynot more than 10¹⁰Ω under a condition of 23° C., in 50% relativehumidity.

When a potassium ionomer is used where ethylene/(meth)acrylic acidcopolymer as a base polymer having too low acid content or the potassiumionomer having too low neutralization degree by a potassium ion, itbecomes not easy to obtain the potassium ionomer or its compositionhaving the surface resistivity in the above mentioned range. Thereforeit is preferable to use a potassium ionomer of ethylene/(meth)acrylicacid copolymer, for example, wherein the content of (meth)acrylic acidis 10 to 25% by weight, preferably 12 to 20% by weight and theneutralization degree by potassium ion is not less than 60%, preferablynot less than 70%.

The polyhydric alcohol is a chemical compound containing two or morealcoholic hydroxyl groups. As such an alcohol, polyoxyalkylene glycol,having preferably a molecular weight of 2000 or less, more preferably1000 or less, such as polyethylene glycol, polypropylene glycol,polytetramethylene glycol, polyoxyethylene/polyoxypropylene glycol;glycerin, trimethylol propane, pentaerythritol, sorbitol, diglycerin,triglycerin, and ethylene oxide adducts or partial esters thereof can becited.

The preferred combined amount of the polyhydric alcohol, for example, isin the range of 0 to 15% by weight, preferably 0 to 10% by weight, basedon the potassium ionomer of ethylene/(meth)acrylic acid copolymer.

As far as the surface resistivity satisfies the above range, ethylenepolymer can be combined with the potassium ionomer or the compositioncomprising the potassium ionomer and polyhydric alcohol. The preferredcontent of the ethylene polymer can be, for example, 0 to 85% by weight,preferably 0 to 80% by weight. As the ethylene copolymer, high pressurelow density polyethylene, linear low density polyethylene, metallocenepolyethylene, a copolymer of ethylene with vinyl ester such as vinylacetate and vinyl propionate, a copolymer of ethylene with anunsaturated carboxylic acid ester such as methyl acrylate, ethylacrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate,n-hexyl acrylate, isooctyl acrylate, methyl methacrylate, dimethylmaleate and diethyl maleate, and a terpolymer of ethylene/carbonmonoxide/vinyl ester or unsaturated carboxylic acid ester can be cited.

(1) A mono-layer sheet, (2) a multi-layer sheet comprising an outerlayer of the composition of the present invention and an inner layer ofthe aforementioned adhesive resin or (3) a multi-layer sheet same as themulti-layer sheet (2) except having a middle layer of potassium ionomeror a composition of the potassium ionomer with a polyhydric alcohol or acomposition further with optional ethylene polymer, can be laminated onthe surface of a substrate by thermal lamination method, heat rollmethod, heat compression molding method, dry lamination method (adhesivecoating method), etc.

As the above substrate, papers or printed papers, various metallicfoils, various metal plates such as steel plate, wooden materials suchas wood or plywood, films, sheets or molded articles of polyolefin suchas polyethylene, polypropylene, TPO, etc, or similar films, sheets ormolded articles containing various fillers, sheets or tiles of PVC andwoven cloths or non-woven fabrics can be cited.

As examples of other extrusion molding of resin composition of thepresent invention, method for heat-bonding the resin composition on asurface of another substrate with extrusion coater to form a laminatecan be exemplified. As the substrate, papers, various metallic foils,various metal plates such as steel plate, films or sheets of polyolefin,woven cloths, non-woven fabrics, etc. can be cited. In the extrusioncoating, good balance between extrusion moldability and surfaceproperties such as abrasion resistance, scratch resistance and mattedappearance can be achieved by managing to control MFR and proportion ofcomponents constituting the resin composition of the present inventionas shown later in Examples.

When the resin composition of the present invention is laminated on thesurface of another substrate by an extrusion coater, the resincomposition may be laminated directly, or laminated through an adhesiveresin layer by a co-extrusion coater. A representative example of theadhesive resin can be a single resin or blended compositions of two ormore resins selected from the aforementioned various ethylene copolymersand grafted products of the copolymers with an unsaturated carboxylicacid.

EXAMPLES

In the following, the invention is explained by examples, but theinvention is not limited to these examples.

Compositions and properties of raw materials used in Examples andComparative examples, and methods used to evaluate properties of sheetsand films obtained therefrom are described below.

1. Raw Materials

(1) Ionomer (A)

Ionomer 1

-   -   Base polymer: Ethylene/methacrylic acid copolymer (methacrylic        acid content: 11% by weight),    -   Metallic cation source: Zinc    -   Neutralization degree: 63% by mol    -   MFR: 5.0 g/10 min        Ionomer 2    -   Base polymer: Ethylene/methacrylic acid copolymer (methacrylic        acid content: 10% by weight),    -   Metallic cation source: Zinc    -   Neutralization degree: 68% by mol    -   MFR: 1.3 g/10 min        Ionomer 3    -   Base polymer: Ethylene/methacrylic acid copolymer (methacrylic        acid content: 10% by weight)    -   Metallic cation source: Zinc    -   Neutralization degree: 80% by mol    -   MFR: 0.9 g/10 min        (2) α-Olefin/Glycidyl Monomer Copolymer (B)        GMA Copolymer:    -   Ethylene/glycidyl methacrylate copolymer (glycidyl methacrylate        content: 12% by weight)    -   MFR: 3.0 g/10 min        (3) Propylene/α-Olefin Copolymer (C)

-   Random PP (propylene/ethylene random copolymer (Grand Polypro F229BA    from Grandpolymer Co., density: 900 kg/m³, MFR: 9.0 g/10 min (230°    C.))

-   Block PP (propylene/ethylene block copolymer (Grand Polypro F707V    from Grandpolymer Co., density: 900 kg/m³, MFR: 6.5 g/10 min (230°    C.))    2. Properties Evaluating Method

Film properties were evaluated by using a blown film of 50 μm thicknessproduced by a method mentioned hereunder. Hot kettle resistance wasevaluated by using a T-die sheet of 200 μm thickness produced by amethod mentioned hereunder. Surface hardness and stiffness were measuredusing a compression molding sheet of 3 mm thickness produced under thecondition of 180° C.×5 minutes heating, 180° C.×5 minutes compressingand 20° C.×5 minutes cooling.

(1) Film Observation (Gel Formation)

Gel formation in the aforementioned blown film was visually examined.

No gel formation: No

Many gels formation: Many

(2) Optical Properties

Gloss: Based on JIS z8741

(3) Retention of Matted Pattern (Visual Qualities)

A test film was placed in a gear oven heated to 180° C. for 1 minute,taken out and cooled to room temperature. Gloss values of the test filmbefore and after the heating were measured to compare each other.

Gloss is greater than before the heating: ×

Gloss is not changed before and after the heating: ◯

(4) Slipping Properties

Based on ASTM D1980A, sliding friction coefficient was measured from theratio of a load (A) when the test film mounted on a holder of 63.5 mmsquare was slipped on the same film fixed on a base at a speed of 150mm/min devided by a load (B) of a holder.

(5) Tensile Properties

Based on JIS K6781, elongation at break and formation of whitening wereevaluated under the following conditions:

Test speed: 500 mm/min

Distance between clamps for holding the test film: 90 mm

Length of line marked on the film for measurement: 40 mm.

(6) Heat Sealability

Based on JIS Z1707, the condition of sealed interface of test film of 15mm width was observed when it was pealed off. For the observation, thetest film was prepared by heat sealing under pressure for 1 second witha 10 mm width seal bar heated to 140° C. and pealed off 24 hours later.

(7) Hot Kettle Resistance

A kettle made of stainless steel containing 2.2 liters of hot waterheated over a gas range was put directly on a test sheet of 200 μmproduced by the method mentioned hereafter, and left for 1 minute. Thehot kettle resistance was evaluated by the observation as follows.

The test sheet was melt to stick the kettle: ×

The test sheet was come off easily from the kettle, but shrunk a little:◯

The test sheet was come off easily from the kettle, and not shrunk atall: ⊚

(8) Surface Hardness

Surface hardness was measured based on JIS K7215 using a 2 mm thicknesssheet produced by the method mentioned hereafter.

(9) Stiffness

Stiffness was measured based on JIS K7106 using a 2 mm thickness sheetproduced by the method mentioned hereafter.

Examples 1-4

A composition obtained by melt-blending GMA copolymer with Random PP orBlock PP, and Ionomer 1 were melt-kneaded in a ratio shown in table 1.Then obtained mixture was molded into a film of 50 μm thickness usingblown film machine in a condition of processing temperature of 190° C.Properties of the film were evaluated. And the obtained mixture was alsomolded into a sheet of 200 μm thickness with single screw extruder of 40mm diameter that is equipped with T-die of 400 mm width under acondition of T-die temperature of 200° C. The hot kettle resistance ofthe sheet was measured.

In addition, a pressed sheet of 3 mm thickness was prepared by a methoddescribed hereunder and used for hardness and stiffness tests.

Results are shown in table 1.

Comparative Example 1

A film of 50 μm thickness, a sheet of 200 μm thickness and a sheet of 3mm thickness were prepared from Ionomer 2 under the similar manner toExample 1 and film properties, hot kettle resistance, hardness andstiffness were evaluated by the same methods as Example 1. The resultsare jointly shown in table 1. TABLE 1 Comp. Examples Example 1 2 3 4 1Raw Materials (Weight Parts) Ionomer 1 93 88 83 88 Ionomer 2 100 GMAcopolymer (2)  (2)  (2)  (2) Random PP (5) (10) (15) Block PP (10)Blended materials 7 12 17 12 Evaluation MFR(g/10 min) 2.2 1.9 2.0 1.31.3 Film observation No No No No No (gel formation) Optical properties(before heating: Gloss) 16 18 21 18 110 (after heating: Gloss) 12 15 2219 120 Retention of matted ◯ ◯ ◯ ◯ X pattern Slipping properties 0.6 0.60.5 0.6 >1.5 (friction coefficient) Tensileproperties >300 >300 >300 >300 250 (Elongation: %) Tensile properties NoNo No No No (Whitening) Heat sealability 1 0.3 0.6 0.3 15 (N/15 mm)(Peeled) (Peeled) (Peeled) (Peeled) (Welded) Hot kettle resistance ⊚ ⊚ ⊚⊚ X Surface hardness 57 58 60 57 55 (Shore D) Stiffness (MPa) 230 240250 240 220

Example 5 Comparative Examples 2-3

A composition obtained by melt-kneading GMA copolymer with Random PP andIonomer 3 were fed to single screw extruder in a ratio of Ionomer 3/GMAcopolymer/random PP=83/2/15 (the weight ratio) and melt-kneaded at resintemperature of 210° C. to get resin composition pellets.

A film of 150 μm thickness was prepared from the pellets with mono-layerblown film machine at resin temperature of 210° C. Stain resistance ofthis film was evaluated using reagents shown in Table 2 according to JISA 5705, A1454 method. Results are shown in Table 2.

In addition as comparison, a sheet of polyvinyl chloride (PVC) of 200 μmthickness having polymerization degrees of 1050 containing 20 parts ofplasticizer DOP which was molded with roll at 160° C., and a film ofcoplymerized nylon 6/66 (UBE nylon 5033 B from Ube Industries, Ltd.) of150 μm thickness which was molded with cast film machine were evaluatedunder the similar manner. The results are shown in table 2.

As appear from above results, the resin composition of the presentinvention shows superior stain resistance. TABLE 2 Comp. Comp. Example 2Example 3 Reagents Example 5 PVC Nylon 6/66 30% Sulfuric acid — — B 35%Hydrochloric acid — A(A) B 60% Nitric acid — B(A) B 100% Glacial aceticacid — — Not measured 5% Acetic acid — — B 10% Citric acid — — A 40%Sodium hydroxide — — A 20% Sodium carbonate — — Not measured 10% Aqueousammonia — — Not measured 28% Aqueous ammonia — — A 5% Phenol aqueoussolution — A B 95% Methanol — A A 95% Ethanol — A A 95% Acetone — A —95% Ethyl acetate — B(B) — 95% Carbon tetrachloride A B(B) — 95% Benzene— B — 95% Oleic Acid — A Not measured Gasoline —(A) B(B) — Kerosene — A— Animal oil (Lard) — — — Milk — — — Soy source — — —Observation results—: No swelling, no color changeA: Slight swelling/(A) slight color changeB: Apparent swelling/(B) apparent color change

Example 6

A three-layer film (thickness: outer layer/middle layer/innerlayer=80/60/60 μm) comprising an outer layer of the resin compositionused in Example 5, a middle layer of a composition composed of 70% byweight of potassium ionomer (neutralization degree: 80%, MFR: 0.6 g/10min) whose base resin is a composition composed of 50 parts by weight ofethylene/methacrylic acid copolymer (methacrylic acid content: 17.5% byweight, MFR: 60 g/10 min) and 50 parts by weight of ethylene/methacrylicacid/isobutyl acrylate copolymer (methacrylic acid content: 5% byweight, isobutyl acrylate content: 10% by weight and MFR: 33 g/10 min)and 30% by weight of ethylene/n-butyl acrylate/carbon monoxide copolymer(n-butyl acrylate content: 30% by weight, carbon monoxide content: 10%by weight, MFR: 25 g/10 min), and an inner layer of a compositioncomposed of 70% by weight of ethylene/n-butyl acrylate/carbon monoxideterpolymer (n-butyl acrylate content: 30% by weight, carbon monoxidecontent: 10% by weight, MFR: 25 g/10 min) and 30% by weight ofethylene/methacrylic acid copolymer (methacrylic acid content: 9% byweight, MFR: 3 g/10 min) was prepared with multi-layer blown filmmachine.

The obtained film and a floor tile made by commercially available PVC(thickness 3 mm) were piled up so that the inner layer of the filmcontacted an outer surface of the tile and heat-pressed at 140° C. for 5seconds with compression molding machine to get a laminated article. Theobtained laminated article has an improved visual qualities, stainresistance and scratch resistance (reciprocating sliding abrasion) atthe surface, and a good adhesion (13 N/25 mm at 90° peeling) between themulti-layer film and the floor tile made by PVC.

Example 7

A three-layer film (thickness: outer layer/middle layer/innerlayer=100/50/50 μm) comprising an outer layer of the resin compositionused in Example 5, a middle layer of a composition composed of 50% byweight of potassium ionomer (neutralization degree: 80%, MFR: 0.6 g/10min) whose base resin is a composition composed of 50 parts by weight ofethylene/methacrylic acid copolymer (methacrylic acid content: 17.5% byweight, MFR: 60 g/10 min) and 50 parts by weight of ethylene/methacrylicacid/isobutyl acrylate copolymer (methacrylic acid content: 5% byweight, isobutyl acrylate content: 10% by weight and MFR: 33 g/10 min),and an inner layer of ethylene/vinyl acetate copolymer (vinyl acetatecontent: 14% by weight, MFR: 2.5 g/10 min) was prepared with multi-layercast film machine.

The obtained film and a 3 mm thickness compression molding sheet of acomposition of 60% by weight of calcium carbonate and 40% by weight ofethylene/vinyl acetate copolymer (vinyl acetate content: 28% by weight,MFR: 15 g/10 min) were piled up so that the inner layer of the filmcontacted an outer surface of the pressed sheet and heat-pressed at 140°C. for 5 seconds with compression molding machine to get a laminatedarticle. The obtained laminated article has good visual qualities, stainresistance and scratch resistance (reciprocating sliding abrasion) atthe surface, and does not cause whitening at bending. The laminatedarticle is suitable for flooring materials.

Example 8

A three-layer film (thickness: outer layer/middle layer/innerlayer=100/30/30 μm) comprising an outer layer of the resin compositionused in Example 5, a middle layer of potassium ionomer (neutralizationdegree: 80%, MFR: 0.6 g/10 min) whose base resin is a compositioncomposed of 50 parts by weight of ethylene/methacrylic acid copolymer(methacrylic acid content: 17.5% by weight, MFR: 60 g/10 min) and 50parts by weight of ethylene/methacrylic acid/isobutyl acrylate copolymer(methacrylic acid content: 5% by weight, isobutyl acrylate content: 10%by weight and MFR: 33 g/10 min), and an inner layer of ethylene/vinylacetate copolymer (vinyl acetate content: 14% by weight, MFR: 2.5 g/10min) was prepared with multi-layer cast film machine.

The obtained film and a printed decorative plywood were piled up so thatthe inner layer of the film contacted the printed surface of thedecorative plywood and heat-pressed at 105° C. for 60 seconds withcompression molding machine to get a laminated article. The obtainedlaminated article has a good stain resistance and scratch resistance(reciprocating sliding abrasion) even without vanish coating at thesurface, and improved visual qualities.

INDUSTRIAL APPLICABILITY

The resin composition of the present invention and molded articlestherefrom show good visual qualities (matted appearance), whilemaintaining the characteristics of ionomer that shows excellent scratchresistance and abrasion resistance, and does not show whitening atstretching or bending. Further as they are superior in heat resistance,matted appearance is retained when exposed to high temperature atsecondary processing etc.

For example, when a multi-layer sheet produced by laminating a surfacelayer comprising the above mentioned resin composition on a substratecontaining foamable resin layer compounded with a foaming agent, afoaming co-agent, an inorganic filler etc, is provided into a foam ovenand foamed, not only an adhesion trouble to a heat roll in the ovenduring foaming is avoided, but matted appearance is not spoiled.

Furthermore, resin composition of this invention and molded articlestherefrom possess an advantage that they show greater film strengthssuch as tear strength and tensile strength at break in comparison withionomer, and further they generate moderate slip properties withoutadditives such as slipping agents or anti-blocking agents. In addition,they possess other advantages such as excellent stain resistancerequired in the outer layer sheet of building materials.

Furthermore, by using propylene/α-olefin copolymer (C), heat resistanceof the composition is largely improved, and sheet strengths such asstiffness or surface hardness is improved in comparison with ionomer.From these characteristics, the resin composition of the presentinvention is suitable for surface layer sheets, decorative sheets, stainresistant sheets or protective sheets of general flooring materials,flooring materials for automobile, building materials for stab boards ofwood or plywood, steel plates and wall papers, furniture and signboard;molded articles such as handrails; leather like covers/skins for carinterior or exterior parts, bags, pocket books and dictionaries; moldedarticles or surfaces for curtains, partitioning sheets, industry usesheets, desk mats, table cloths, mouse pads, marking films, toys andstationery; carpet surface or bottom; sheets to be used in vacuum formprocess.

1. A thermoplastic resin composition comprising 60 to 96.7 parts by weight of (A) an ionomer wherein 20 to 90% of carboxyl group of ethylene/(meth)acrylic acid copolymer is neutralized by metal ion; 0.3 to 10 parts by weight of (B) a copolymer of ethylene or α-olefin, containing glycidyl (meth)acrylate or unsaturated glycidyl ether, optionally further containing vinyl ester or unsaturated carboxylic acid ester; and 3 to 30 parts by weight of (C) propylene/α-olefin copolymer.
 2. The thermoplastic resin composition according to claim 1, wherein at least part of metal ion in the ionomer (A) is divalent metal ion.
 3. A process for manufacturing the thermoplastic resin composition described in claim 1, which is characterized by melt-blending the ionomer (A) with melt-blended mixture of (B) the copolymer of ethylene or α-olefin, containing glycidyl (meth)acrylate or glycidyl unsaturated ether, or optionally further containing vinyl ester or unsaturated carboxylic acid ester and (C) the propylene/α-olefin copolymer.
 4. A molded article comprising the thermoplastic resin composition described in claim
 2. 5. The molded article according to claim 4, wherein the molded article is a surface material for a multi-layer material.
 6. A multi-layer material comprising the surface material described in claim 5 laminated onto a mono-layer substrate or a multi-layer substrate.
 7. The multi-layer material according to claim 6, wherein at least a part of the substrate is a foamed layer.
 8. A molded article comprising the thermoplastic resin composition described in claim
 1. 9. The molded article according to claim 8, wherein the molded article is a surface material for a multi-layer material.
 10. A multi-layer material comprising the surface material described in claim 9 laminated onto a mono-layer substrate or a multi-layer substrate.
 11. The multi-layer material according to claim 10, wherein at least a part of the substrate is a foamed layer. 